If you're following the development of Vista, you'll have heard the perhaps-exciting but perhaps run of the mill news that Vista RC1 is now complete. Anyone participating via MSDN or TechNet will be able to get the official RC1 package next week, and those participating in TAP or TechBeta are able to get it immediately. MS is quite excited about it:

You'll notice a lot of improvements since Beta 2. We've made some UI adjustments, added more device drivers, and enhanced performance. We're not done yet, however --- quality will continue to improve. We'll keep plugging away on application compatibility, as well as fit and finish, until RTM. If you are an ISV, RC1 is the build you should use for certifying your application.
This is good news to vendors eagerly awaiting the official retail release, especially with all the concerns over potential future delays as January approaches.